The Mediterranean Sea is a vital habitat for several of the ocean’s largest animals. A recent assessment confirms that at least eight species of cetaceans – including dolphins, whales, and beaked whales – are regularly found in its waters, with others visiting sporadically. This makes the Mediterranean a significant, though increasingly vulnerable, marine ecosystem.
Cetaceans, which include whales, dolphins, and porpoises, originated approximately 50 million years ago in the ancient Tethys Sea from terrestrial mammals, according to research into the evolution of the group. Today, around 80 species exist globally, but the Mediterranean hosts a concentrated population of several key species.
Among the most commonly observed is the striped dolphin (Stenella coeruleoalba). These dolphins are characterized by a dark or bluish-gray dorsal side and a white ventral side, marked by black lines running along their flanks. Mediterranean striped dolphins tend to be slightly smaller than their Atlantic counterparts, reaching lengths of up to 2.2 meters. They are known for their acrobatic displays, frequently leaping more than seven meters into the air, and often gather in groups ranging from five to fifty individuals, though larger aggregations of hundreds have been recorded.
The Mediterranean’s cetacean populations face increasing threats, notably from illegal drift nets. These nets pose a significant risk to large whale species. Efforts to mitigate these dangers are being coordinated through the Agreement for the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS), established in 2001.
Scientists are also working to identify critical feeding grounds for marine megafauna in the Mediterranean, including cetaceans, large fish, turtles, and birds. A recent study utilizing “energyscapes” – a combination of satellite tracking data and ecological modeling – has estimated that approximately 4.1 million large predators consume around 1.6 million tons of prey each summer in the Mediterranean, particularly in the western basin. This research highlights the importance of protecting these habitats to support the region’s diverse marine life.
The study, involving researchers from the Spanish Institute of Oceanography (IEO) and the Institute of Marine Sciences (ICM) of the Spanish National Research Council (CSIC), estimates the scale of biomass consumed by these animals and underscores the demand for effective ecosystem management. The Mediterranean Sea, described as a dynamic and vulnerable ecosystem, requires continued monitoring and conservation efforts to ensure the long-term survival of its cetacean populations and other marine megafauna.
